Constraint Induced Therapy (CT)

I first read about Constraint Induced Therapy in Norman Doidge's book, The Brain that Changes Itself. I heard an interview with Doidge on the radio and immediately bought the book. It has had a profound impact on Peter's stroke recovery. Most importantly, it gave us hope.

If the only action you take from reading our website is to buy and read this book - please DO IT! (There is a link to the book on Amazon on the right hand side of this page.)

Dr Edward Taub's Research

Dr Edward Taub leveraged on the concepts of brain plasticity to develop Constraint Induced Therapy. Basically, brain plasticity is the ability of the brain to reorganise itself to support the functionality that the person is focusing on and working on. When a stroke occurs and a person suffers hemiplegia, they start to use the non-affected side of their body and avoid using the affected side. This is termed learned non-use.

Dr Taub's work goes back to 1981. At this time he was conducting animal experiments. Deafferentation is a technique of severing sensory nerves so that their responses are not being passed back to the brain. Dr Taub did this to one arm of his lab monkeys. Technically, there was nothing wrong with the deafferented limb, however the monkey had no sensory input from the limb which meant it could not sense where the limb was in space or feel any sensation from the limb. The monkeys quickly stopped using the deafferented limb. (Can you see where this is going? Deafferentation is like the impact of a stroke ... there is nothing wrong with the affected limb, but the stroke patient's brain can't get it to work.)

The next part of the research was to see if the monkeys could be forced to use the affected limb. This was accomplished by constraining the unaffected limb with a sling strapped to the body. Incentive, in the form of food, was provided. The monkeys were forced to use their affected limb if they wanted to eat. And they did!

Indeed, there was an interesting twist to this. If both arms were deafferented, the monkey never lost capability of either limb. However, if one was deafferented, then capability was lost in that limb. This is where the theory of learned non-use came from. In the post-surgery period, whilst an effect known as spinal shock occurred, the monkey tried to use its arm and couldn't, so it learned to use the other one instead. In the case of both limbs being deafferented, the monkey didn't have a chance to learn that a limb wasn't working well because it needed the limb to feed itself.

Principles of CT

Dr Taub translated these learnings into a practical application for stroke patients and called it Constraint Induced Therapy.

There are three principles underlying Constraint Induced Therapy:

• Constraint - use of the non-affected limb is physically constrained
• Forced use - the patient is forced to use the affected limb
• Massed practice - the patient does intensive repetitions of the activity.

Further to this, the effort should be directed towards activities of daily living (ADL) to give purpose and context for the patient.

Results

Patients who have undergone CT have been shown to significantly recover function in their affected limb.

A recent study by Dr Taub in 2006 verified the success of CT over traditional therapy. A group of stroke patients were split into two groups - one group received CT and the other a general fitness program, cognitive training and relaxation exercises. All patients participated in the study for six hours per day for 10 consecutive weekdays. It's also important (and encouraging) to note that on average patients were 4.5 years after their stroke.

The CT patients showed a "large to very large" improvement in the functional use of their affected arm for activities of daily living, whilst those in the control group showed now improvement. In addition to the improved functionality, the CT patients were faster in completing tasks during lab testing.

Beyond the study, the CT patients showed a further large improvement two years later whilst the control group showed no improvement.

The implication from the improvement is that once a patient rises above the learned non-use, they can get more and more out of the limb as they involve it more in daily activities.

If you Google "constraint induced therapy", you will see that there are many references to other studies. All of the ones that I've reviewed support the study recounted above, with patients showing significant improvement. It's also disappointing to see that most links are to research being conducted, rather than to practical application and specific therapists who can offer this therapy. It's still a long way from being a mainstream therapy offered to stroke patients.

Since I wrote the above, I've noticed that more information is coming into the public domain. Here is an interesting YouTube video showing a KCAL9 news story on Constraint Induced Therapy.

How It Works

Constraint Induced Therapy is incredibly intensive, with patients being required to attend all day for consecutive days for the duration of the treatment period (typically six weeks). The unaffected limb is immobilised (through a sling and a mitt). Therapists work pretty much one-on-one with patients, providing the activities, encouraging and pushing them to the next level of performance. Outside of the clinic, patients are required to continue to wear the sling and mitt in all waking hours.

Because of the intensity, CT is expensive and generally not reimbursable through health insurance or provided in public programs. Accordingly, most patients are self-funded and the therapy is limited to those who can afford it.

Further to the complexity, the constraint of the sling and mitt is onerous. Surveys of patients indicate that in the order of 80% are unwilling or unlikely to comply with the discipline required of them.

In addition to support for physical disabilities arising from stroke, constraint induced therapy has been used for those suffering from aphasia (language disability). In this area, some practical solutions have been identified and these can be sourced from the internet.

What Next?

Research continues in this field. Dr Taub is working on Auto-CITE, a computer-based means to deliver CT. However, at the time of writing, this has not been commercialised and does not appear to be available outside of the research laboratory.

Most encouraging though, has been the development of Modified Constraint Induced Therapy, which makes the therapy less onerous and appears to be delivering similarly effective results.